The Asian longhorned tick continues to spread through U.S. states bordering Canada. While the tickhas not been detected in Canada, the parasite it can carry, Theileria orientalis Ikeda, was confirmedin an imported dairy cow in October 2025. This parasite can cause significant illness, productionlosses and long-term impacts on herd health.

Our new fact sheet provides producers with:
Access the fact sheet here.
Produced by Animal Health Canada in collaboration with theCanadian Animal Health Surveillance System (CAHSS)Longhorned Tick Task Force to raise awareness about thepresence and potential risks of the Asian longhorned tick andTheileria orientalis Ikeda (November 2025)